The present invention relates generally to a workpiece processing machine, and more particularly to a worktable of the workpiece processing machine.
The ordinary workpiece processing machine, such as a circular saw or woodworking machine, has a worktable serving as a platform for placing a workpiece to be processed and for acting as a basis for moving the workpiece. In theory, a worktable with a greater area for placing the workpiece is good for the workpiece to be processed in various fashions. However, an excessively large worktable is sure to give an added volume and an additional weight to the workpiece processing machine, thereby resulting in an increase in cost of transportation of the workpiece processing machine.
The German Utility Pat. No. 2980112711 discloses a circular saw comprising a main worktable, and two auxiliary worktables which are provided in two sides thereof with a round rod that is received in one of two long through holes of the main worktable, thereby enabling each auxiliary worktable to be pulled to slide along the axial direction of the round rod so as to adjust the size of the workpiece placing area which is formed together by the main worktable and the two auxiliary worktables. The volume of the entire worktable can be made smaller by joining the auxiliary worktables with the sides of the main worktable. The space that is taken up by the circular saw can be thus minimized. In addition, the circular saw can be shipped with a relative ease.
The locating effect of the auxiliary worktables is attained by a plurality of wing bolts, which are fastened with the main worktable such that they can be pressed against the round rods of the auxiliary worktables. These bolts are apt to become unfastened by the vibrational motion of the circular saw in operation, thereby undermining the locating effect of the auxiliary worktables. The workpiece can not be therefore stabilized on the main worktable and the auxiliary worktables. In addition, it is inconvenient and time-consuming for a machine operator to fasten or unfasten the wing bolts in an effort to locate the two auxiliary worktables.
It is therefore the primary objective of the present invention to provide a workpiece finishing machine with a worktable which is designed to hold workpieces of various sizes.
It is another objective of the present invention to provide a workpiece finishing machine with a worktable which is easy to use.
In keeping with the principle of the present invention, the foregoing objectives of the present invention are attained by a worktable comprising a first worktable, a second worktable, and a locating device. The first worktable has a first joining portion. The second worktable has a second joining portion which is slidably joined with the first joining portion such that the second joining portion slides in a reciprocating manner along a predetermined direction, thereby enabling the second worktable to move toward or away from the first worktable. The locating device comprises an arresting member having a first friction portion, and an actuating mechanism which is mounted on the second worktable and is connected with the arresting member. The arresting member is actuated to move back and forth between a first position and a second position such that the arresting member is located at the second position. The second worktable has an urging portion, which urges the actuating member to move aside at the time when the arresting member moves from the first position to the second position, thereby enabling the first friction portion to attach to the second friction portion. As the arresting member arrives at the second position, the second friction portion presses against the first friction portion. As a result, the second worktable can not be continuously moved and is thus located.